Infectious Bronchitis Virus &dash; Phylogenetic tree

Phylogenetic tree comparing the relatedness of the sequence of the S1 part of the spike glycoprotein of IB variants from USA and other parts of the world.

Key

Ark&equals;Arkansas

Beau&equals;Beaudette

CAV&equals;California variant

Conn&equals;Connecticut

CU-T2&equals;Cornell University

D1466&equals;Dutch isolates

D207

D274

DE072&equals;Delaware isolate.

Fla&equals;Florida

GAV&equals;Georgia variant

Mass&equals;Massachusetts

UK/167/84&equals;United Kingdom isolate

Variant 1 and Variant 2 are from Israel

As a general rule, isolates less than 89&percnt; similar are different serotypes, with the exception that Conn 46 and Fla 18288 are 96&percnt; similar but are different serotypes, indicating that only a few changes in the right place are required to change the serotype.